Flexible bags for use in the containment of various items, as well as the preservation of perishable materials such as food items, are well known in the art. Such bags typically comprise a rectangular sheet of polymeric film folded upon itself and sealed along two edges to form a semi-enclosed container having two flexible opposed sidewalls, three sealed or folded edges, and one open edge. A closure integrally formed with the bag such as an interlocking rib-type seal, drawstrings, ears, or flaps, or separately provided such as a plastic or paper-clad-wire tie, completes the containment assembly.
As utilized herein, the term "flexible" is utilized to refer to materials which are capable of being flexed or bent, especially repeatedly, such that they are pliant and yieldable in response to externally applied forces. Accordingly, "flexible" is substantially opposite in meaning to the terms inflexible, rigid, or unyielding. Materials and structures which are flexible, therefore, may be altered in shape and structure to accommodate external forces and to conform to the shape of objects brought into contact with them without losing their integrity. Flexible bags of the foregoing variety are typically formed from polymeric film, such as polyethylene or other members of the polyolefin family, in thicknesses of between about 0.0002 inches to about 0.002 inches. Such films are frequently opaque and/or colored, but may also be transparent.
Conventional flexible bags create an inherent challenge in terms of being able to hold the flaccid bag in an open condition with at most one hand so that the other hand can manipulate another container to pour the contents into the bag or peel, cut, or trim items for insertion into the bag. Accordingly, it is common practice to use such flexible bags as a reusable, replaceable liner in a supporting device such as a hoop or rigid or semi-rigid container having an opening approximately corresponding to the size of the mouth of the bag. In order to avoid having the bag fall inside the supporting device and render the mouth of the bag closed or inaccessible, it is also common practice to draw the mouth of the bag laterally outwardly of the opening in the supporting device and downwardly for at least a small extent over the flange, lip, or upper edge of the supporting device to frictionally engage the supporting device. Such measures as tying knots in the mouth of the bag to reduce its circumference and retaining devices such as elastic bands are also sometimes utilized. One common scenario for illustrative purposes is the use of plastic trash bags as liners in reusable, durable trash containers.
While this approach has become commonplace, difficulties remain in that it is sometimes difficult to match the size of the bag with the size of the supporting device. Also, when frictional engagement is less than required the action of placing items within the flexible bag has a tendency to cause the mouth of the bag to creep upwardly toward the flange, lip, or upper edge of the supporting device to the point where the mouth of the bag may slip free from the rim of the supporting device.
Another issue with this approach is that air and/or free space may be trapped between the exterior surface of the flexible bag and the interior surface of the supporting device when the initially empty flexible bag is inserted into a larger, typically largely-enclosed rigid or semi-rigid durable container and frictionally or tightly engaged with the rim of the container by folding or stretching the bag material. Such a situation frequently limits the ability to fully utilize the full volume potential of the flexible bag as the trapped air prevents the bag from expanding to approach the interior volume of the durable container.
While flexible bags of the foregoing variety have enjoyed a fair degree of commercial success, their reliance upon mechanical closures tends to cause difficulty in operation for individuals having impaired manual dexterity such as children, the elderly, arthritis patients, etc. Moreover, such mechanical closures typically require alignment of mechanical elements for operation which can prove challenging for those with impaired vision or impaired hand-eye coordination. Many mechanical closure mechanisms also provide leakage sites at such locations as the end of interlocking channels where liquid or gases can leak into or out of the bag. Other closure designs often require the user to engage in tying or twisting motions.
In an attempt to address this issue alternative closure mechanisms have been developed which rely upon strips or regions of adhesive to bond superimposed regions of the bag. While these closures address some of the difficulties in utilizing separate closure elements or interlocking mechanical elements, some adhesive closure mechanisms require removable liners to protect the adhesive from premature activation, thus adding additional elements for assembly and an additional activation step before use. Moreover, some protected adhesive configurations require interlocking grooves, channels, or protrusions which must be properly registered to engage the adhesive, thus again raising the visual and coordination requirements of conventional mechanical closure mechanisms.
Accordingly, it would be desirable to provide a flexible bag which is capable of reliably engaging a supporting device so it may be supported in an open condition for filling purposes.
It would also be desirable to provide such a flexible bag which reduces the likelihood of trapped air and/or free space occurring when the bag is utilized with a rigid or semi-rigid durable container.
It would further be desirable to provide a flexible bag having improved sealability in use.
It would still further be desirable to provide such a bag which provides the foregoing attributes in a convenient unitary form, obviating the need for separate closure devices.